We assumed that in the future humans, or other biological entities, would receive mechanical or electronic 'upgrades'. It looks like it could be the other way around. Machines might be getting biological upgrades.

Adding computer chips to someone's brain is a long way away, but adding neurons to a computer may be just around the corner. Researchers have just added nerve cells to specially-constructed semi-conductors, and the results seem to indicate that one day, biological nerve cells will be strung through computers. We won't put the ghost in the machine - we'll put the meat in it.

This particular step in human/machine evolution was taken at the University of Wisconsin-Madison. Researchers constructed little tubes of silicon and germanium. These tubes are often used in computer technology, but they were chosen mostly for their ability to insulate the electric impulses that run down nerve cells. After the network of tubs had been constructed, mouse nerve cells were added to the structure. The tubes were specially sized so that the main bodies of the cells were too big to fit inside them, but the long axons - the slender 'arms' of the cells - were perfectly able to fit down the tubes. After a little while, the nerve cells has threaded themselves into the network of tubes.

This represents a very promising direction in mechanical-biological integration, but it also signals that the integration might not go the way we've been expecting. Machines are still struggling with things like walking, recognizing pictures, and the basic manipulation of objects. Humans have no such difficulty. In the future, instead of putting robot hands on a human, they'll put human hands on a robot - and have them controlled by human neurons going to a basic human brain.